Dacryocystitis is inflammation of the lacrimal sac which typically occurs secondarily to obstruction within the nasolacrimal duct and the resultant backup and stagnation of tears within the lacrimal sac.
Anatomy: Tears are produced by the lacrimal glands; paired almond shaped exocrine glands which sit in the upper lateral portion of each orbit in the lacrimal fossa, an area found within the frontal bone. The tears lubricate the eye and are then collected into the superior and inferior puncta and then drain into the inferior and superior canaliculi. From the canaliculi, the tears pass through the valve of Rosenmuller into the lacrimal sac where they then flow down the nasolacrimal duct, through the Valve of Hasner, and finally drain into the nasal cavity.
The etiology of dacryocystitis can be divided into acute, chronic, acquired and congenital causes.
Acute dacryocystitis is typically infectious in origin. In the United States the common causal agents in children agents include Staphylococcus aureus, B hemolytic Streptococcus and Pneumococcus and Haemophilus influenzae. Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus pneumoniae and Pseudomonas aeruginosa are the most common causes in adults. 
Chronic dacryocystitis is due to chronic obstruction of the nasolacrimal system. Common etiologies include systemic disease, dacryoliths, repeated infection, and chronic inflammatory debris within the nasolacrimal system.
Acquired causes of dacryocystitis include trauma such as nasoethmoid fractures, surgeries such an endoscopic or endonasal sinus procedures, neoplasms, and certain medications such as timolol, pilocarpine, idoxuridine, and trifluridine.
Congenital forms of dacryocystitis are typically due to obstruction of the valve of Hasner, located in the distal portion of the nasolacrimal duct. If amniotic fluid is not expelled from the nasolacrimal system a few days following delivery, it can become purulent, leading to neonatal dacryocystitis. 
Dacryocystitis has a bimodal distribution; most cases occur after birth (congenital dacryocystitis) or in adults greater than 40 years of age (acute dacryocystitis). Congenital Nasolacrimal duct obstruction occurs in approximately 6% of newborns, and dacryocystitis occurs in 1/3884 live births. In adults, females are more commonly affected than males, and Caucasians are more commonly affected than African Americans ,
The risk factors for dacryocystitis are varied but are almost always related to nasolacrimal duct obstruction.
- Females are at greater risk due to their narrower duct diameter as compared to males
- Older age leads to narrowing of the punctual openings, slowing tear drainage
- Dacryoliths; often idiopathic, a collection of shed epithelial cells, lipids, and amorphous debris within the nasolacrimal system
- Nasal septum deviation, rhinitis and turbinate hypertrophy
- Damage to the nasolacrimal system due to trauma of the nasoethmoid region or endoscopic and endonasal procedures
- Neoplasm within the nasolacrimal system
- Systemic disease such as Wegener’s granulomatosis, sarcoidosis, and Systemic Lupus Erythematosus (SLE)
- Medications such as timolol, pilocarpine,idoxuridine, and trifluridine
Dacryocystitis typically occurs secondary to obstruction of the nasolacrimal duct. Obstruction of the nasolacrimal duct leads to stagnation of tears in a pathologically closed lacrimal drainage system, with the stagnated tears providing a favorable environment for infectious organisms. The lacrimal sac will then become inflamed leading to the characteristic erythema and edema at the inferomedial portion of the orbit. 
Symptoms and Signs
Presentation differs for acute and chronic dacryocystitis. In acute dacryocystitis, the symptoms may occur over several hours to several days and is characterized by a sudden onset of pain, erythema and edema of the medial canthus and the area overlying the lacrimal sac at the inferomedial portion of the orbit. The redness commonly extends to involve the bridge of the nose. Very often, purulent material can be expressed from the puncta, and tearing may be present. In cases of chronic dacryocystitis, excessive tearing is the most common symptom. Increased tearing may lead to the production of a tear film and mattering; the collection of debris and denuded epithelial cells from the surface of the eye due to obstruction of drainage of the mucous layer of the tear film. Changes in visual acuity may be present due to tear film production
Erythema involving the entire orbit and pain with extraocular movement are not typically associated with dacryocystitis and should prompt the health care provider to search for alternative diagnoses.
The diagnosis of dacryocystitis is generally made clinically based off of the patient’s history and physical exam, as described above. In acute cases, a Crigler, or tear duct, massage can be performed to express material for culture and gram stain. In patients who appear to be acutely toxic or those who present with visual changes, laboratory and blood tests should be considered, and may reveal leukocytosis. In chronic cases, serologic testing can be performed if systemic conditions are suspected. For example, antineutrophilic cytoplasmic antibody (ANCA) testing may be useful to test for granulomatosis with polyangiitis (formerly Wegener's) while antinuclear antibody testing (ANA) can be used if systemic lupus erythematosus is suspected.  Imagining is not typically needed for diagnosis. CT scans may be performed in cases of trauma and Dacryocystography or plain film dacrosystogram (DCG) can be performed when anatomic abnormalities are suspected. Nasal endoscopy is useful to rule out hypertrophy of the inferior turbinate, septal deviation and inferior meatal narrowing.
The fluorescein dye disappearance test (DDT) is another option available to evaluate for adequate lacrimal outflow, especially in patients unable to undergo lacrimal irrigation. In a DDT assay, sterile fluorescein dye if instilled into the conjunctival fornices of each eye, and the tear firms are then examined under a slit lamp. The persistence of dye coupled with asymmetric clearance of the dye from the tear meniscus after five minutes, indicates an obstruction. 
· Acute ethmoid sinusitis
· Infected sebaceous cysts
· Eyelid ectropion
· Punctal ectropion
· Allergic rhinitis
· Lacrimal sac or sinonasal tumor
Treatment of acute dacryocystitis includes conservative treatment such as warm compresses and Crigler massages. Lacrimal probing is discouraged in acute cases. For uncomplicated cases, oral antibiotics with gram positive coverage should be given. Complicated cases require IV antibiotics. Recurrent infections may require surgical evaluation by an ophthalmologist.
Lacrimal probing is the recommended treatment of chronic dacryocystitis, however most patients eventually require surgical treatment. Available surgical techniques include balloon dacryoplasty, nasolacrimal intubation, and nasolacrimal stenting. If unsuccessful, percutaneous dacryocystorhinostomy (DCR) or endonasal dacryocystorhinostomy (EN-DCR) may be performed. 
In cases of congenital dacryocystitis, treatment begins conservatively with Crigler massages (parents are taught how to perform the massage at home), and antibiotics are prescribed for the treatment of acute flares. 90% of cases resolve by one year with conservative measures. The patients who fail conservative treatment often undergo lacrimal probing, which is successful in 70% of cases. In still unsuccessful, surgical interventions are needed. 
Prognosis and Complications
Fortunately, the prognosis of dacryocystitis is generally positive, but devastating complications are possible, and prompt referral to an ophthalmologist is encouraged. Possible complications include the formation of lacrimal fistulas, lacrimal sac abscesses, meningitis, cavernous sinus thrombosis, vision loss and possibly death.
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